A human heart includes four heart valves that determine the pathway of blood flow through the heart: the mitral valve, the tricuspid valve, the aortic valve, and the pulmonary valve. The mitral and tricuspid valves are atrioventricular valves, which are between the atria and the ventricles, while the aortic and pulmonary valves are semilunar valves, which are in the arteries leaving the heart. Ideally, native leaflets of a heart valve move apart from each other when the valve is in an open position, and meet or “coapt” when the valve is in a closed position. Problems that may develop with valves include stenosis in which a valve does not open properly, and/or insufficiency or regurgitation in which a valve does not close properly. Stenosis and insufficiency may occur concomitantly in the same valve. The effects of valvular dysfunction vary, with regurgitation or backflow typically having relatively severe physiological consequences to the patient.
Recently, flexible prosthetic valves supported by stent structures that can be delivered percutaneously using a catheter-based delivery system have been developed for heart and venous valve replacement. These prosthetic valves may include either self-expanding or balloon-expandable stent structures with valve leaflets attached to the interior of the stent structure. The prosthetic valve can be reduced in diameter, by crimping onto a balloon catheter or by being contained within a sheath component of a delivery catheter, and advanced through the venous or arterial vasculature. Once the prosthetic valve is positioned at the treatment site, for instance within an incompetent native valve, the stent structure may be expanded to hold the prosthetic valve firmly in place. One example of a stented prosthetic valve is disclosed in U.S. Pat. No. 5,957,949 to Leonhardt et al. entitled “Percutaneous Placement Valve Stent”, which is incorporated by reference herein in its entirety. Another example of a stented prosthetic valve for a percutaneous pulmonary valve replacement procedure is described in U.S. Patent Application Publication No. 2003/0199971 A1 and U.S. Patent Application Publication No. 2003/0199963 A1, both filed by Tower et al., each of which is incorporated by reference herein in its entirety.
Although transcatheter delivery methods may provide safer and less invasive methods for replacing a defective native heart valve, leakage between the implanted prosthetic valve and the surrounding native tissue may occur if not accommodated for by a particular implant. For instance, leakage may occur due to the fact that deployment of a minimally invasive cardiac valve is intended to occur without actual physical removal of the diseased or injured heart valve. Rather, the replacement stented prosthetic valve is contemplated to be delivered in a compressed condition to the native valve site, where it is expanded to its operational state within the native valve. Calcified or diseased native leaflets are to be pressed to the side walls of the native valve by the radial force of the stent frame of the prosthetic valve. However, it has been shown that calcified leaflets do not allow complete conformance of a stent frame with a native valve and therefore this ill-fit within the native anatomy may be a source of paravalvular leakage (PVL), as significant pressure gradients across the implanted prosthetic valve may cause blood to leak through the gaps between the implanted prosthetic valve and the calcified anatomy.
Embodiments hereof are related to transcatheter valve prostheses having one or more components attached thereto or integrated thereon to address and prevent paravalvular leakage.